Compilare: user.cpp: In function ‘int main()’: user.cpp:9: warning: format ‘%c’ expects type ‘char*’, but argument 2 has type ‘int*’ user.cpp:15: warning: format ‘%c’ expects type ‘char*’, but argument 2 has type ‘int*’ user.cpp:7: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:8: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result